Gas-engine



Patented l'an. 24, 1899,.

E. E. WULF.

EAS ENGINE.

(Application led June 25, 1897.)

5 Sheds-Sheet I.

(No Model.)

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.l nl' AXIIIJ HIIII/I/IIIII. u I

No. 6l8,l57. Patented lan. 24, |899. E. E. WOLF.

GAS ENGINE.

(Application led June 25, 1897.)

5 Sheets-Sheet 2.

(No Model.)

o a o o e n w mv @y No. 6i8,|57.

E. E. WOLF.

GAS ENGINE.

(Application led June 25, 1897.;

Patented 1an. 24, |899.

5 Sheets-Sheet 3.

(No Model.)

.w NVN No. 6|8,l57. Patented 1an. 24, |899. E. E. WOLF.

GAS ENGINE.

(Application med June 25. 1897.)

5 Sheets-Sheet 4.

(lo Model.)

mL-moms PETERS oo4 PHovau-mo wAsHmoToN, o c

Patented lan. 24. |899.

5 Sheets-Sheet 5.

E. E. WOLF.

GAS ENGINE.

(Application tiled June 25, 1897.) (No Model.)

554.3% @Hom/w iINiTnn STATES PATENT FLMER E. IVOIJF, OF SPRINGFIELD,OI'IIO.

GAS-ENGINE.

SPECIFICATION forming part of Letters Patent No. 618,157, dated January24,- 1899.

Application filed June 25, 1897i T0 all who/1t t may concern;

Be it known that I, ELMER E. WOLF, a citizen of the United States,residing at Springfield, in the county of Clark and State of Ohio, haveinvented certain new and useful Improvements in Gas-Engines, of whichthe following is a specification, reference being had therein to theaccompanying drawings.

This invention relates to certain new and useful improvements in rotarygas or gasolene engines.

The essential object of my invention is to take up the power of thecylinder and the power of the piston, both of which assume momentum whenthe charge is exploded, and to carry the power derived from these twosources to a common driving device or pulley, so that the combinedmomentum or power of the cylinder and piston, both of which arepropelled by the explosive force, is converted into rotary motion andtransmitted to this common driving device or pulley for utilization inoperating either portable or stationary machinery.

lVith this end in view the essential features of my invention consist ofa wheel carrying one or more cylinders and a piston or pistons for thecylinder or cylinders, combined with a system of gearing and cranks,with suitable intermediate devices, by which the movement of the pistonor pistons is transferred -to such gearing, by which it is convertedinto rotary motion and transmitted back into the main wheel, which wheelis also given a rotary impulse by the explosion of the charge as thecylinder is forced in one direction and the piston in the other, and ofa driving device or pulley connected with the main wheel and therebytaking up these two rotary forces.

My invention also embraces a number of other features or objects,together with the means for carrying them into practical effect, all ofwhich will be hereinafter more fully described, and particularly pointedout in the claims.

In the accompanying drawings, on which like reference letters andnumerals indicate corresponding parts, Figure l is a partial verticalsectional view and partial side elevation of myimprove'd engine. Fig. 2is a detail edge view of a part of the main wheel, showing a removablesection which constitutes the pis- Serial No. 642,336. (No model.)

ton-head; Fig. 3, an enlarged detail View of the piston-pinion and itscranks; Fig. 4, a transverse vertical sectional view of my improvedengine entire, the section being taken on the line y 'y of Fig. l,looking in the direction of the arrows; Fig. 5, a detail end view of apart of the gasolene-pump devices; Fig. 6, a partial edge view andtransverse sectional view of the engine, the section being taken on theline s z of Fig. l, looking in the direction of the arrows; Fig. 7, adetail sectional view of a part of the wheel-hub and of the stationarycasing, showing the several ways and passages for water and air; Fig. 7,a detail view of the double rocking arms; Fig. 8, a partial sideelevation and sectional view ofthe engine, the section being taken onthe line x :c of Fig. 4, looking in the direction of the arrows; Fig. 9,a side elevation of the engine entire with a few parts broken away tofacilitate the illustration; Fig. 10, a detail sectional view on theline z z of Fig. 9, showing the manner of insulating and connecting thecasing and the plate that carries the igniting-cam; and Fig. 1l, adetail sectional view on the line y y' of Fig. 9,v showing the means foradjusting this plate and its cam and the arrangement of the severalparts.

The letter A designates a stationary bearing in which is rotatablymounted a wheel B,

having a sleeve C, which fits in the bearing and is connected with themain wheel D, as shown at E. Thus this wheel is rotatably supported atone side. The letter F designates a stationary casing having apackingring G, in which is rotatably mounted the hub H of the main wheelD. Thus the other side of'this wheel is rotatably supported and thusalso it will be seen that this wheel may rotate in bearings beyond eachside of it. The bearing A and stationary casing F are themselvessupported in any manner desired. In this wheel I form or secure one ormore cylinders, preferably two. For this purpose I cut out of the rim ofthe wheel a section I, which I secure by bolts J. I then fit cylindersKin the wheel structure, as more clearly shown in Fig. l, and as I formthe wheel with walls L, which encircle the cylinders, as more clearlyshown in Fig. 4, it will be seen that I leave a water space or jacket M,into which IOO water is fed through an inlet-passage composed of a tubeO, formed on the stationary casing F and discharging through a slot P(see Fig. 9) into an annular groove Q, formed in the outer face of thehub H of the main wheel, (see Figs. 4 and 8,) from which the waterpasses through slots Rinto passages S, (see Fig. 8,) formed in the wheelstructure and discharging into the water-jacket M, as seen at T inFig. 1. The Water flows out of the water-jackets through the passages U,(see Fig. 4,) which extend through the structure and through the hub, asshown at V, and finally open into an annular groove W in the hub, whencethe water discharges into tubes X, formed on the stationary casing F.(See Figs. 6 and 9.)

In each of the cylinders is a reciprocating 1 piston a, provided with apitman b, the outer end of which is pivoted to a rocking arm or lever c,mounted upon a fulcrum-pin d, secured in bearings e, formed in the wheelstructure and in the shell B. (See Figs. l and 6.) This arm has a sleevef, so that the portion G' of the arm which connects with the pitman band the portion cl of the arm extend from the sleeve f in such positionsas that the portion c will be in the plane of the pitman b, while thepart CZ will be in the proper plane to connect with the wrist-pin g ofthe piston-pinion h through a pitman t'. (See Figs. l, 3, 6, and 7%)Thus it will be seen that when the piston a. moves outward it willimpart its motion through these parts to the pinion 7L, which I term thepistonpinion, because it takes its motion from it, and thus convert aright-line motion of the piston into a rotary motion in the pinion.These parts are clearly shown in Fig. l in their relation to one anotherand it will be understood that when the piston is making an outwardstroke it is also traveling in a circular path with the main Wheel, andthe result oi' this is that at the time when the piston begins to moveoutward the pitmant' will stand at such an angle to the wrist-pin g ofthe pinion h as to thrust such wrist-pin downward or in the direction ofthe arrow seen in Fig. 1, so that the pinion h is made to rotate in thatdirection. Now I have so far described one cylinder and its piston andthe connection between such piston and pinion wrist-pin of thepiston-pinion. A like or similar connection between the other piston andthis pinion is also included; but for the sake of greater clearness Iwill refer to these like connections by specific reference-letters. Thepinion 71, has also a wrist-pin j, these wrist-pins g and j beingconnected by a cross-arm k, and the wrist-pin j having a crank-arm Z,provided with a hollow spindle m, (see Fig. 3,) adapted to be mounted inthe sleeve C, as shown in Fig. 4, so as to support this crank structure,for such it is at this end, the other end being supported by the pinion71. itself. The wrist-pin j is connected by a pitman o to the doublerocking. arm p, having a sleeve q, mounted upon a fulcrum-pin o, itselfhaving bearings in the shell B and in the Wheel structure just the sameas shown and described above with respect to the fulcrum-pin d. In Fig.4 it will be seen that the parts s of this second arm p connect with thepitman t of the other piston, a portion of which piston is seen at u,the balance being cut ott by reason of the direction of the section, asshown by the line y y of Fig. l. The arrangement is exactly the same, asmore fully shown, as to the other piston appearing in the sectional partof Fig. 1. Figs. 4 and 6.) Thus it will be seen that when the pistonsmake their outward strokes their movement is transmitted to thepistonpinion h and that in the transmission it is converted from aright-line movement to a rotary movement and is applied to the pinion hupon opposite sides of the center of the crank structure of the pinionand in opposite directions, so that no binding of the parts isexperienced, but rather a true and etcient mechanical transmission isperformed. Of course it will be also understood that the pitman o byreason of the rotary movement of the main wheel will have assumed at thetime the motion is being transmitted a similar relation to the wrist-pinj as that above described with respect to the pitman t' and thewrist-pin g. Having thus traced the passage of the motionof the pistonsinto the pistonpinion, I will novi7 show how this motion is carriedthence into the main wheel, so as to join with the power that isexerting the rotary influence upon this wheel by reason of the backaction7 vor reaction as it may be termed of the explosions as they actagainst the cylinder-heads, which are a part of the wheel structure,being formed of the sections I. The piston-pinion h being mounted upon astud-shaft fu, which rotates in a stationary sleeve w, carried by thestationary casing F, it meshes with two pinions 2 and 3, rotatablymounted on studs 4, projecting from this stationary sleeve fw. Caps 5and screws 6 serve to keep the pinions 2 and 3 on' these studs. Thesepinions in turn mesh with the gear or pinion 7, secured to the wheelstructure, as shown at 8, and rotatably mounted on this stationarysleeve w. Hence it will be seen that the rotary motion of the pinion hpasses first into the pinions 2 and 3 and thence out of them into thepinion or gear 7 and over it into the main wheel D. The di- (See alsoyIOO IIO

IZO

rection of rotation of the main wheel is indicated by the arrow 9 inFig. l, and it is in this direction that the rotary motion of the pinionh is finally transmitted into the main Wheel, and so this main wheelgets rotary motion both from the pistons as they move outward and fromthe cylinder-heads as they recede under the explosive force; but thisrotary motion of the wheel D is taken up by the shell B, which is formedinto a pulley l0 as one type of means for transmitting this rotarymotion to the machinery to be operatedsay the driving-wheel of amotor-cycle--as I contemplate using this engine more particularly forthat purpose, though itis applicable to any purpose where power isneeded.

I will now refer-to the means for introducing gasolene into the enginewhen gasolene is used; but it will be understood that my enginegenerally is adapted to be used with gas by applying to it the detailedmechanism necessary to feed the gas to the ports that lead to thecylinders.

A rod 11 is rotated by the pinion 7L, and on this rod is fitted a collar12, having ears 13, in which are pivoted governor-arms 1,4,interconnected by springs 15 and each provided with anantifriction-roller 16, adapted to engage with either of the segmentalsteps 17 on a lever 18, fulcrumed in an arm 19 and bifurcated at itslower end, as seen at 20, to engage with notches in the sides of ahollow. piston-rod 2l, mounted on the rod 11 and engaged at its innerend by a spring 22, thrusting outwardly on it from a stop 23. iVhen thelever 18 is pushed inward by the governor, as its antifriction-roll 16passes along one or the other of the steps 17 this whole pistonrod 21 isgiven an instroke and as the governor leaves these steps this piston isgiven an outstroke by the spring 22. A pistonv24 on the piston-rod 2lworks in the part 25 of the stationary sleeve u', which Jforms apumpbarrel, and thus a pumpis constituted, which draws the gasolene pasta check-valve 26 in a supply-pipe 27 and then forces this gasolenethrough a valve-seat 2S, having a valve 29, seated by a spring 30 in thesleeve w. The gasolene passes into this sleeve and mixes with the airentering at the orifice 31, thus constituting this part of the sleeve anair and gasolene barrel, and thence the two together pass out of theorifice 32 in the wheel-hub H and into the annular groove 33, and thencethrough the passages 34 (see dotted lines in Fig. S) and into theinlet-valve casing 35, see Figs. 6 and 8,) and thence past the valves 36into the chest 37, formed in the wheel structure, as particularly seenin Fig. 6, and from this chest into the explosive-space 38 of thecylinder, as more clearly seen in Fig. 1. This construction is the samefor both cylinders. The exhaust products pass also out of the chest 87,past the valve 39, (see Fig. 6,) into the valve-casing 40 and out of thepassage 41 to the slot 42 into the annular passage 43, whence it escapesinto the tube 44, formed on the casing F. (See Figs. 6, 8, 4, and 9 inthe order of this description.)

Referring now to the inlet-valve 36 and the exhaust-valve 39, it will beseen that they have stems and each stein a cap 45 and 46, respectively,held to their respective stems by the pins 47 and that springs 4S seatthese valves after they are opened by cams acting upon the caps 45 and46. These cams are stationary curved plates suitably inclined andattached to the stationary casing F, so that as the valves rotate, withthe wheels, past these cams their caps 45 and 46 travel upon these camsat the proper time. are shown particularly in Figs. 6 and 9. The cam forthe inlet-valve 36 is shown at 49 and held by bolts 50, and the cam forthe exhaustvalve is ,shown at 51, being held by bolts 52.

The air-orifice 31 above referred to is upon opposite sides of thesleeve w and is ted by two tubes 53, formed on the casing F, and thesetubes may be open either at their ends or at their sides, as shown at54.

I will refer now to the electrodes by which the sparking is effected andthen to the means for operating the electrodes. From Fig. 1 the positionot the electrode is most clearly shown in its relation to the cylinderand in Fig. 6 the construction is best illustrated. Both electrodes arealike, so that a description of one will suffice. A thimble and a Thecams thimble 56 are fitted to the Wheel structure,

and a tubular bearing 57 for the electrode is fitted in these thimblesand insulated from them by insulating material 58. The electrode properis made of two rods 59 and 60, the rod 59 being slidingly fitted to thetubular bearing 57 and rod 60 having a head 61 slidingly fitted to thethimble 55. A spring 62 keeps the shoulder 63 of one rod seated againstthe thimble 55 and a spring 64 keeps the other rod projected outward, sothat its cap 65 will keep in contact with the cam 66, by which it isoperated inward to bring its contact-point 67 against the contact-point68 of the other rod. This action presses both of the springs. )Vhen thecap 65 passes oft the cam, both rods return to normal position, and whenthe shoulder 63 strikes the thimble 55 the rod 60 is arrested, while therod 59 moves on, and thus the contact-points 67 and 68 are suddenlyseparated and a spark produced. The thimble 55 is slotted, as shown at69, to allow the spark and charge to communicate. Referring to the meansfor operating the electrodes, the same consists of said cam 66,slidingly fitted to a plate 70, (see Figs. 9 and 11,) which is fittedover a slot 71 in the wall of the stationary casing F and insulated fromthe casing by insulation 72. The plate 70 has a IIO slot 73, in whichare fitted bolts 74, projecting from or through the cam 66. Tp one ofthe bolts is attached a cam-strap 75, mounted on a cam 76, having ahandle 77 and pivoted on a stud 7S, projecting from the plate 70 andlocked in adjusted positions by a hand-wheel 79, screwed upon a stud 7S.A wing SO projects from the casing F and has a scale and a slot 81, inwhich is an adjustable stop 82 in the nature of a bolt and nut. The stop83 limits one movement of the handle 77, while this adjustable stop 82may be set opposite any of the figures on the scale, which figuresrepresent the number of revolutions the main wheel will make per minute,each piston making two complete revolutions, as ordinarily understood,to each revolution of the main wheel-that is, each piston makes twooutstrokes and two instrokes to one revolution IZO of the main wheel.Now by adjusting the handle 77 to any one of the lines on the scale thecam 66 will be adjusted so as to operate the electrode at the propertime for the best eifect for the number of revolutions of the main wheelindicated by the figure adjacent to such line-that is to say, if theengine-governor is so set that the main wheel will make ive hundredrevolutions per minute the handle 77 will be adj usted to the 50077line. This is done so that the cam 66 will be in position to operate theelectrode at the proper time for that speed. It takes about so much timeto complete combustion from the time the charge is ignited, and thistime is constant irrespective of the speed of the engine. Therefore thefaster the engine is going the sooner the electrodes must be operatedwith respect to the moment when the pistons pass the inner dead-centerand begin the powerstroke. If the piston is traveling rapidly, it willreach the extreme inner position sooner than if traveling more slowly,and so in order to spark and complete combustion at the proper time theelectrodes must be operated sooner or later, according to the speed ofthe piston, sooner if the speed is great and later as the speed isless.v This I accomplish by adjusting the cam 6G to the given positionsindicated by the figures on the scale. Thus the cam is adjusted to suchposition as that the electrodes will leave it in time for the spark tobe produced when the pistons complete or substantially complete theinstroke. A series of bolts S4 connect the plates 70 with the casing F.

I will now refer to the conductors for conducting the current to theelectrodes. Wires S5 from the generator connect with posts 86 and 87,insulated from but connected to the casing F. To the post 86 is secureda springconductor 8S, adapted to be touched by the caps of theelectrodes as they revolve with the main wheel, the current passingthrough the rod 59 to the contact-point 67. To the post 87 is secured aspring-conductor S9, there being insulating material 90 and 91 betweenthese spring-cond uctors and the casing F. This conductor 89 is adaptedto be swept against by the surface 92 of the electrodes. The currentpasses thence through the wheel structure, cylinder, and thimble 55 tothe contact-point 68. (See Figs. 6 and S.)

Referring again to the governor, (see Figs. 4 and 6,) a nut a', held bya jam-nut IJ', is adjusted to prevent the governor-arms from drawing inmore than might be desired, so as to prevent the antifriction-rollers 16from coming in contact with such of the steps 17 as would give too greata charge of gasolene for the particular conditions under which theengine might be started. The post c permits the arm 19 to be adjusted todifferent positions, so as to change the stroke of the piston 24 foreach step 17, thus making it a double adj ustment-one by the steps andone by the position of the arm 19.

It will be seen,

too, that the wider the step upon which the rolls 16 press during a partof their revolution the longer the instroke of the piston 24 will be,and hence the greater the amount of gasolene that will be ejected.

As a means of oiling the cylinders I provide a cup d', (shown in dottedlines in Fig.

4,) communicating with an oil-orifice e in vspecial mechanism shown anddescribed I have incorporated into an engine the principle or mode ofoperation of carrying to a common pulley or power-transmitting devicethe combined momentum and force of the piston or pistons and cylinder orcylinders as they receive impulses from the repeated explosions of thecharge, such impulses acting in a manner that may be termed direct onthe pistons and by reaction on the cylinder-heads. This mode ofoperation, coupled with the other factor that the piston or pistons andcylinder or cylinders are, besides their relative movements, undergoingrotation about a common center and are carried by a body which forconvenience I have term ed the main wheel,7 I regard and believe to bewholly new, and hence wish to be understood as laying broad claimthereto.

Vhile I have referred to the power-transmitting pulley or device anddescribed the same as consisting of the pulley 10, I Wish to beunderstood as including within the term power-transmitting pulley ordevice any part of the main wheel from which the power may be taken tooperate outside machinery, and this is the sense in which said term isused in the claims hereto appended.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. In a gas -engine of the character described, the combination with amain wheel, one or more cylinders carried thereby and apower-transmitting pulley or device, of a piston for each cylinder, andintermediate devices consisting of a connection of pitmen, rocking armand central crank, the latter having its central line in line with thecenter of said .main wheel, and intermediate devices between said crankand the power-transmitting pulley adapted to transmit motion from theformer to the latter, substantially as shown and described.

2. In an engine of the character described, the combination with themain Wheel, a transmitting pulley or device and one or more cylinderscarried by said wheel, of a piston for IOO IIO

cach cylinder, a piston-pinion, and rotatable pinions between it andsaid wheel, and connections between said piston-pinion and the piston orpistons. t

3. In an engine of the kind described, the combination with the mainwheel, a powertransmitting pulley or device and cylinders carried bysaid wheel, of pistons in said cylinders, a central gearing consistingof a pistonpinion, a main-wheel pinion, and intermediate pinions, andcrank-pitmen, and arm connections between the pistons and piston-pinionadapted to apply the power of the pistons rotatably upon opposite sidesof the pistonpinion center.

4. In an engine of the character described, the combination with themain wheel, a transmitting pulley or device secured to it and cylinderscarried by it, of reciprocating pistons in said cylinders, a rocking armand pitmen for each piston, a central piston-pinion having a doublecrank connected with two of said pitmen, a main-wheel pinion andintermediate pinions connecting it with the pistonpinion for the purposedescribed.

5. In an engine of the character described, the combination with themain wheel, a powertransmitting pulley or device, cylinders carried bythe wheel, a piston foreach cylinder, intermediate devices between eachpiston and the power-transmitting pulley or device, and electrodes, aninlet-valve and an exhaustvalve carried by said wheel, and inlet, eX-haust and water inlet and outlet passages in said wheel structure, and astationary casing having tubes for said passages, cams for saidelectrodes and valves carried by said wheel, a gasolene-pumpcommunicating with said inlet-passage and a governor connected with saidpump, substantially as described.

G. In an engine of the character described, a main wheel one or morecylinders with their pistons carried thereby, charge inlet and exhaustpassages, water inlet and outlet passages formed in the wheel structure,a hub and a stationary casing having tubes or conduits for saidpassages, and a gasolene-pump communicating through the center of saidcasing and through the hub with the chargeinlet passage.

7. In a gas-engine of the character described, the combination with astationary casing carrying a sleeve forming in part a pump-barrel and inpart an air and gasolene barrel, of a revoluble shaft passing throughsaid sleeve, a governor carried by said shaft, a pump-piston on saidshaft, means between the governor and piston to operate the piston inone direction by the action of the governor, and a spring to operate thepiston in the other di- 4 rection, a suitable valve between saidbarrels,

charge-passage leading from the latter barrel to the engine-cylinder, amain wheel carrying said cylinder and having said passages formed in it,of a revoluble shaft passing through said sleeve, a governor operated bysaid shaft, a piston on said shaft, and a device between the piston andgovernor for operating the piston, a gasolene-supply leading to thepump-barrel and a suitable valve between said barrels, and av spring tooperate the piston in the opposite direction to that by the governor.

9. In an engine of the character described, the combination with acentral stationary sleeve, a main Wheel revoluble about said sleeve, ashaft revoluble in said sleeve, a charge-passage from said sleeve tocylinder or cylinders in said wheel, an air-orifice and gasolene-supplyleading into said sleeve, a valve between them, a piston on said shaft,and a governor on the shaft with means between the governor and pistonto actuate the latter.

IO. In an engine of the character described, a revoluble shaft, agovernor operated thereby, a piston on said shaft, a lever connected tosaid piston and ha/ving steps of various sizes engaged by said/governorduring a part of its rotation.

l1. In an engine of the character described, a revoluble shaft, agovernor thereon, means to regulate the approach of the governor-arms, alever having a movable fulcrum and varioussized steps engageable by thegovernor according to its speed, and a piston on said shaft connectedwith said lever.

l2. In an engine ofthe character described, the combination with astationary casing having a sleeve and an oil-orifice, of a main wheelrevoluble about said sleeve and having an annular groove and one or morecylinders cornmunicating with said grooverthrough oil-orifices, theorifices of the sleeve discharging into said groove, whereby thecylinders may be lubricated.

13. In an engine of the character described, the combination with a mainwheel having one or more cylinders, and an electrode for each cylinder,of a stationary but adjustable actuating means for said electrode orelectrodes, said means being adapted to be adjusted to cause theelectrode or electrodes to spark at variable times with respect to thedead-center position of the piston or pistons.

14E. In an engine of the character described, the combination with amain wheel carrying one or more cylinders, and an electrode for eachcylinder, of a stationary structure, a cam adjustably connectedtherewith but 1ocated in the revolving path of said electrode orelectrodes and adapted to be adjusted to disengage from said'electrodeor electrodes at different times in the circuit of rotation.

' l5. In an engine of the character described, the combination with astationary casing, and an insulated plate secured thereto, of a cam ICOIIO

slidably connected with said plate and means mounted on the plate andconnected with the cam to adjust the same.

16. In an engine of the character described, the combination with astationary casing, a plate insulated therefrom, and a scale, of a camslidingly connected with the plate, an eccentric arm mounted on theplate and connected by a strap with the cam and adapted to be swung todifferent positions on the scale, for the purpose described.

17. In an engine of the character described, a main wheel carrying oneor more cylinders and a piston for each cylinder, and a system ofcentrally-located gearing consisting of a pinion connected with thepiston or pistons, a pinion connected with said wheel and pinionsinterconnecting said other pinions.

18. In an engine of the character described, the combination with a mainwheel having a power-transmitting pulley or device at one side and ahul) at the other, of a stationary bearing for said pulley or device anda station ary casing having a flange in contact with said hub, wherebythe wheel is revolubly mounted.

19. In a gas-engine of the character described, the combination withstationary spring-conductors, of arevolving wheel stru cture, andelectrodes carried thereby and adapted to revolve past saidspring-conductors whereby one of said spring-conductors will make awiping contact with one of the electrodes and whereby the other of saidspring-conductors will make a wiping contact with the wheel structureadjacent to the electrodes.

In testimony whereof I ax my signature in presence of two witnesses.

ELMER E. \VOLF.

Witnesses:

W. M. MCNAIR, JAs. C. DAWLEY.

